Service devices, such as service couplings, are commonly employed to facilitate charging and evacuation of a pressurized fluid system, such as a refrigeration system, an air conditioning system, or a hydraulic system. The service device connects to a service port of the system. The service device opens a valve within the service port, allowing fluids, including liquids or gases, to be exchanged with the system. For example, when servicing a refrigeration or air conditioning system, the service device can be connected by a flexible hose to a refrigerant supply source, such as a pressurized bottle or cylinder or a recovery and recycle station. When the service device and valve within the service port are opened, refrigerant can flow through the connection and into the refrigeration or air conditioning system.
In air conditioning systems, system performance can deteriorate when air is in the system. In addition, introduction of air can also lead to introduction of moisture and other contaminants into the system. Thus, keeping air out of the system can be important when servicing a system.
In order to properly open a valve within the service port, the valve must be positioned properly within the service port so that the service device can open the valve when connected to the port. Deviations in valve position within the port can cause the service device to improperly open the valve, fail to open the valve, or damage the valve by applying excessive pressure to the valve.